Mobility Not Metal is an impressively clear and comprehensive account of the potential of the driverless car revolution – with a significant omission that we will come to shortly. It provides an intelligible description of both the technology on which it depends, and the extraordinary pace of its development. The essence of the mobility vision it presents is a world transported by Uber without the drivers. It also presents convincing evidence that it will be possible for this technology to operate safely for all road users, both in and outside cars.

Bridges is clear that driverless cars will be a massively disruptive technology, and identifies the potential winners and losers in the revolution that he forecasts. Per mile travelled it will be hugely cheaper, safer and more efficient for all travellers, but especially for those denied a driving licence because of age, disability or disqualification. The potential losers include the motor manufacturing industry (far fewer cars will be needed), motor mechanics (the new “Autos” will be much more reliable and less expensive to maintain) and an army of drivers (from those driving taxis and delivery vans to pizza delivery boys on bicycles). He is clear that the gains will greatly exceed the losses – driverless cars “will have a profoundly positive influence on all of us and our planet as well” – and that the winners will prevail – Chapter 1 is entitled “How your world will [not might] change.”

He argues his case with the help of a number of American vignettes: “For simplicity’s sake, we’ll focus just on mobility services in the U.S., provided to city and suburban markets by electric vehicles.” More specifically his demonstration of the economic advantages of driverless cars is based on their potential use in Denver: “The City and County of Denver will be the theoretical test market for the Mobility economic model.” And herein lies a problem.

Bridges’ vision of the future of driverless cars is global – he speaks of its impact on “our planet” – and he envisages its principal market being “densely populated metro areas” everywhere. But by global standards the city and county of Denver are not densely populated. 82% of its commuters currently travel by car, truck, or van, mostly from sprawling suburbs. The other favourite demonstration laboratory for driverless cars is Mountain View California also, by global urban standards an area of extremely low settlement density. How, one might ask, would the self-driving car cope in a truly densely populated metro area such as London with a population density more than 150 times that of Mountain View?

This question is not addressed. Truly densely populated urban areas have dense pedestrian traffic and, increasingly, dense cycling traffic. And, after many decades of neglect, it is now official policy in most such areas that these modes of travel should be encouraged. How might driverless cars manage in such areas?

Most of the video demonstrations of driverless cars that I have been able to find show them performing on roads from which cyclists and pedestrians have been excluded. Where they are shown interacting with pedestrians and cyclists the pedestrians and cyclists are very occasional impediments, and the driverless cars are shown responding very deferentially. They are, according to Bridges, “inherently polite” and programmed to be “the ultimate defensive drivers”. It is difficult to see why, at the busy times of day when driverless cars would be most in demand, they would not suffer deferential paralysis in areas with high volumes of pedestrian and cycle traffic.

Bridges observes “it could be the regulatory challenges and not technology that pose the greatest risk for bringing the benefits of driverless cars to the people of the planet.” He fears that America might not rise to these challenges and asks: “Will America let politics and bureaucracy block real progress?” If not he fears that China might steal the lead in the race to bring his vision of progress to the world.

But he offers no clue as to how the challenges posed by high pedestrian and cyclist densities might be met. What regulatory changes would be needed to allow Autos free movement in such areas? His book does not acknowledge the existence of the problem. A challenge readers might find interesting: Google “China (or Netherlands) bicycles” and click on images, and then devise a set of regulatory changes that would allow Bridges’ Autos to share the streets with the traffic in the pictures displayed.

Buy this book. **** is a compromise. This is essential reading for those seeking to understand the evangelical enthusiasm of the advocates of driverless cars and the extraordinary wealth and political muscle of their promoters, and fearful of the consequences for pedestrians and cyclists who threaten to impede their progress.

Kate Carpenter says:

July 26, 2015 at 12:15 pm (UTC 0)

great review. Does the book cover what for me is the thorniest issue, of the shoulder of change – with a mix of full autonomy (stopping for every pedestrian/cycle) and full manual (including novice drivers with propensity for poor anticipation and rear end shunts?) I’m also interested in the complex mental model drivers have of time as well as space: I know i need a different lane at one time of day than another, and this herd knowledge increases traffic efficiency; it seems likely that full autonomy would require simpler layouts, fewer lanes (all those places where we have 2 or 4 lanes plus a part-marked sub-right-turn lane. how would the autonomous vehicle position itself in such a situation?) The issue of density in our cities is central for me – the complexity is very high, and autonomy seems to need simple disney-clear layouts of lanes.

I also fear that cheaper easier taxis will reduce walking and cycling including by children travelling to school) with greater inactivity-driven heath impacts.

The brave new world is exciting – and the devil is in the detail, especially in the phasing while full manual 20 year old cars mix with semi-and full autonomy. It seems this detail is yet to be thrashed out…

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Kate
Thanks for all this. You have hit on lots of the things that are bothering me – and will shortly, I hope, lead to another essay on the subject. JA

As a computer scientist who has watched the evolution of the computer industry for 50 years I find it all too probable!

As a cycle campaigner I don’t yet know what to think about driverless cars. We need a discussion forum to clarify our thinking on the topic.

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George – thanks for the Cycling Front link. A superb essay. Deserves wider exposure than it is likely to receive on the Cycling Front website. Do you know the author?